Attached Link: http://www.toucan.co.jp/product/3ds/garden/modelsE.html

Did you by any chance get these from Toucan's? Because if so, he has modified all his meshes and they now render beautifully. Just a couple of days ago I imported them all (in 3ds format) and resaved them all as props. Since they come with maps that means they've already been uvmapped hence no need to turn them into .obj's, only makes the mesh bigger. In case you didn't get them from Toucan's do so right now! :) And if you're interested check out the fish as well, also very great models http://www.toucan.co.jp/product/3ds/3dsFrameSetE.html